Move by tenths
A tenth moves ten hundredths at once.
Decimal Zoom Lens
Explore decimal place value through linked whole and magnified tenth number lines.
Grades 4–5 · Math
Your goal
Move the lens marker to 0.35. Use tenths for large moves and hundredths for small moves.
Reduced motion is on. The controls still update the scene.
0.00 has 0 whole, 0 tenths and 0 hundredths. The zoomed interval runs from 0.00 to 0.10. Ten hundredths make one tenth.
Values are stored as whole hundredths, so every step is exact. The lower line magnifies one tenth; it is a different scale from the upper line.
Related resources
Related cheat sheets
Related labs
Study as flashcards
Learn with Decimal Zoom Lens
Decimal Zoom Lens links a broad number line from zero to two with a magnified view of one tenth. Upper elementary students move a marker by tenths or hundredths and see the corresponding digits in separate place value cards. The lower line divides the highlighted tenth into ten equal hundredths, making small distances easier to inspect. Nine goals include values below one, values above one, and movement across whole number boundaries. The live feedback supports discussion of carrying between places and the different scales used by the two linked views.
What to look for
Inspect the lens
The bottom line enlarges the highlighted interval, not a new whole.
Watch a carry
Step from 0.99 to 1.00 and describe which digits change.
For teachers and curious learners
Relate hundredths and tenths to the same whole. Ask students to predict what will happen, change one setting, and explain what they observe. Learn gives a starting point. Practice and Challenge offer new goals with the same scene.
Decimals are stored as integer hundredths between zero and two. The magnified interval contains ten hundredths. At 2.00 the lens shows the final tenth ending at two.